1. Field of the Invention
The present invention relates generally to electrical enclosures.
2. Description of the Background
There are various sizes, shapes, and designs of electrical enclosures. Many electrical enclosures are designed in a manner such that it is impossible to eliminate all high voltage (typically greater than 50V) from the inside of the enclosure without opening a main supply breaker, which can also mean losing power to other equipment. For example, FIG. 1 is a typical electrical enclosure 10 to which a main power supply line feeds into the enclosure 10 and to a Main Power Disconnect 30 located within the enclosure 10. Each motor is controlled by an individual circuit breaker also within the enclosure 10, and external disconnect switches 1-4. Main Power Disconnect 30 is mechanically linked to a manual actuator 40 that locks/unlocks the door. The manual actuator 40 requires the Main Power Disconnect 30 switch to be turned “OFF” before the door of the electrical panel 10 is released to open. With the manual actuator 40 in “OFF”, and the door opened, there is still a high voltage potential within the electrical panel enclosure 10, accessible to human hands or tools or others, at the terminals of the Main Power Disconnect 30. Additionally, if one or more of the contacts of the Main Power Disconnect 30 have failed and it remains shut (ex, welded) despite the manual actuator 40 being in “OFF”, there is still high voltage within the electrical panel enclosure, and in this latter case it is unknown to the technician. Unless it is somehow possible to turn off main power before it enters the electrical enclosure 10, work cannot be performed on/in the electrical enclosure 10 without an inherent high voltage condition. OSHA requires the use of electrical safety precautions for work in the vicinity of energized gear. Work in the vicinity of energized gear, even with electrical safety equipment, still presents a level of risk, but to use all this equipment in practice requires significantly more time, cost, and equipment.
Some business, such as the U.S. Postal Service has a significant quantity of electrical enclosures designed in this manner. In adherence of electrical safety precautions, as practice they use additional electrical safety equipment (e.g., face shields, safety glasses, rubber gloves, rubber matting, coveralls, etc.). This equipment is expensive and because of sizes, companies may be required to have many sets. Further, it requires significantly more time to work on equipment, which may sometimes only be a very quick task. Employees may also, in an effort to complete their work task quickly, violate policy of using electrical safety equipment and put themselves at risk.
It would be greatly advantageous to provide an improved electrical enclosure that avoids the above-described high voltage condition, as well as a retrofit method for modifying an existing electrical enclosure as above with a low cost easy to install kit, which will eliminate the high voltage condition, creating a safer work environment for many companies, including the U.S Postal Service.